Several subjects are more ill-suited to comedy than identity theft: undergoing a root canal procedure, watching your house burn down, learning a beloved pet has died.

Still, the notion of a person having his finances ransacked by a stranger doesn’t promise hours of hilarity, and the makers of “Identity Thief” realize this. After setting up the professional and emotional devastation Jason Bateman’s character suffers when his identity is stolen, the movie does its best to say, “You know what? Forget about that. Laugh at the crazy car crashes instead.”

Bateman’s character is a mensch, a mid-level functionary in a Denver financial services firm with a beautiful wife (Amanda Peet, who deserves to be in better movies), two darling daughters and a lifestyle they can just about afford. A phone call from an identity thief played by Melissa McCarthy threatens all this.

Because Bateman has the androgynous name Sandy Patterson (he prefers to call it “unisex”), McCarthy is able to appropriate his name and his credit card information. In short order, Bateman’s bank informs him his accounts are overdrawn and his credit maxed out, the police arrest him for a crime he didn’t commit in a state he never visited and his boss (John Cho) wants to fire him.

Once Bateman learns that a woman in Florida is the real criminal, he convinces the police he can bring the woman to Denver and she will confess to defrauding him. Why he believes she will cooperate is a mystery. Of course, McCarthy is not the pushover he expected. Their initial encounter ends with him smashing a guitar into her face.

Bateman soon coerces McCarthy into his rented sedan. They set off for Denver, and “Thief” eventually settles into a sentimentality it by no means earns.

Although director Seth Gordon (“Horrible Bosses”) takes a long time to reach this point, “Thief” is basically a road comedy. It borrows the specific formula John Hughes established in “Planes, Trains and Automobiles,” which was recycled just recently with Robert Downey Jr. and Zach Galifianakis in “Due Date.” A straight-laced family man is forced to journey with a weirdo.

If “Thief” sticks to the formula, Bateman will recognize McCarthy’s loneliness and see her in a new light. Heartening stuff, but John Candy never willfully destroyed Steve Martin’s credit rating.

Proving more like “Due Date” than “Planes, Trains,” “Thief” involves its characters in an array of traffic accidents that in reality would kill them. One miraculous non-fatality is presented rather graphically. If this were an action movie, it would be a henchman’s death scene.

To partially explain why McCarthy is willing to hit the road with Bateman, she is being pursued by a pair of killers as well as a skip tracer (Robert Patrick). The developments don’t make much sense, but screenwriter Craig Mazin (working from a story he conceived with Jerry Eeten) probably read those script manuals that call for “complications,” so here they are.

Mazin includes many of the cliché scenes of a road comedy, such as fighting over the car radio and spending an embarrassing night at a cheap motel. Also on display is the standard establishing shot of the characters’ car passing the St. Louis Gateway Arch to demonstrate they are halfway into their journey.

The script is episodic and clunky. Much time is wasted at the start with Bateman taking a new job. The only reason for the second job is to set up Bateman’s first boss, a smarmy one-percenter played by Jon Favreau, as a convenient foil in the third act. Favreau’s scene is the best in the movie. Explaining why “people like me” deserve million-dollar bonuses, he says. “I’ll get you a copy of ‘The Fountainhead.’ You’ll read it, and you’ll understand.”

Although they are trapped within the script’s slippery morality, Bateman and McCarthy find ways to be charming. This may be the best version yet of the everyman persona Bateman has created for himself. McCarthy, first seen in garish makeup and brightly colored outfits that make her look grotesque, discovers moments here and there where her over-the-top antics can be funny.

This is another version of McCarthy’s breakthrough performance in “Bridesmaids,” the wild woman who turns out to have hidden wisdom. The late revelation about her character in “Bridesmaids” was touching, but her character in “Identity Thief” does not deserve such empathy.

This woman is an unrepentant thief who probably destroyed many lives before Bateman’s. If we like the character, it is because we are used to laughing at the talented woman who plays her. But McCarthy should beware repeating this pattern. At some point acting offensive and obnoxious won’t be hilarious. It will just be offensive and obnoxious.